[css-module] Replace "Animatable" by "Animation Type" (#8423)

Author: cdoublev

css-module/Overview.bs

@@ -125,7 +125,7 @@ Internal display model: the 'foo' property {#the-foo-property}
 		Inherited: no
 		Percentages: n/a
 		Computed value: specified value
-		Animatable: no
+		Animation Type: not animatable
 		Canonical order: per grammar
 	</pre>